Prunes (dried plums) are a popular food item providing a good source of vitamin C as well as other vitamins and nutrients for consumers. As such, there is a continued need to develop prune trees with increased yield and quality of plums for the production of prunes.
The long term commercial success of “French-type” prunes, both the European ‘Prune d'Ente’ and Burbank's ‘Improved French’, suggests that they will be desirable parents for new cultivars. However, there are several problems involved in incorporating these cultivars directly into a breeding program. Relatively few seedlings from these cultivars express substantial maturity spread, a major industry need. Seedlings of “French” origin are often weak in vigor and slow to come into bearing (up to eight years). These unproductive (juvenile) years greatly extend the breeding cycle. In addition, most seedlings solely derived from this parentage do not attain the level of production of the parent and have a wide range of variability in adaptation to climatic conditions. Even the best selections from France are generally not adapted to California climatic conditions.
Thus there is a tremendous need for developing new prune varieties utilizing “French-type” prune trees in breeding where the resulting trees that express precocity of bearing (shortened juvenility), spread of maturity (both early and late), freedom from heat damage (in both fruit and tree) and vigorous seedling growth.